Using Barcode printer for Online Control to generate, create GS1-128 image in Online applications.

18 CS 17 DIN 16 SSTRB 15 DOUT 14 DGND 13 AGND 12 REFADJ 11 VREF

7 CS 6 DOUT 5 GND

DAO 00774400 Bottom View

CH5 6 CH6 7 CH7 8 VSS 9 Bottom View

78L05

MAX187

1 1 1 1 1 1 1 1 1 1 1

78L05

SHDN 10

MAX186

Figure 24-2 Semiconductor pin-outs output of the regulator U1 When inserting the IC into its socket pay particular attention to the orientation Pin one (1) of the IC must be inserted into pin one (1) of the IC socket Note that there will be a notch or cut-out or small indented circle on the top of the IC package Pin one (1) of the IC will be just to the left of the cut-out or notch One neat way to package the units is inside a two way parallel port manual switch box These can be bought for about $10 at computer shows One of the DB25 connectors is removed from the back of the switch and replaced with a power and a analog input jack Leads 2, 3, 12, 24 and 25 from the removed DB25 are soldered directly to the appropriate places on the A to D board The switch can then be used to pass through to the printer when the A to D is not in use You could also elect to mount the A/D converter in a small plastic box if desired with a 25 pin connector on the rear of the enclosure Before applying power to the A/D circuit, take a moment to inspect the foil side of the PC board Pick up the PC board with the foil side of the board facing upwards towards you We are going to examine the PC board for possible cold solder joints and short circuits before applying power for the first time Look carefully at the solder joints, they should all look clean, shiny and bright If any of the solder joints look dark, dull or blobby then remove the solder from the joint and then re-solder the joint all over again Next, we will examine the PC board for possible short circuits which are often caused by the sticky rosin residue left on the circuit board from the solder Often cut components or small solder balls can adhere to the foil side of the board and short between the circuit traces Once you have examined the PC board carefully, you can go ahead and power-up the circuit for the first time Install the free A/D collection software, either Data Collect Lite or Radio-Sky Pipe from the Radio-Sky web-site, or see Appendix, and start collecting data from one of your new receivers In the event the circuit does not work, check over the installation of the electrolytic capacitors and the polarity of the power supply connections The MAX87 chip should be available from Digi-Key Corporation, see Appendix

ADC 2: 8 channel analog to digital converter

An 8 channel 12-bit analog to digital converter (ADC) project is shown in Figure 24-3, and connects to the

parallel port of your personal computer This second low cost analog to digital converter circuit is one you can readily build yourself in a few hours from scratch This A/D converter works with free software from a company known as Radio-Sky, which specializes in products for Radio Astronomy Their free software, which works with the low cost ADC, is called RadioSky Pipe The ADC is based on a single low cost integrated circuit from MAXIM Semiconductors Pins 1 through 8 on the MAX186 A/D converted chip correspond to Channels 1 through 8 A 100 kilo-ohm resistor is placed across each input channel pin and is connected to ground The A/D converter circuit connects to a personal computer via the parallel port You will need to choose the appropriate parallel port address which is selected in the free Radio-Sky Pipe software Note that all of the 1 F (microfarad) capacitors are non-polarized types, typically disk ceramic capacitors They should be rated for at least 15 volts The A/D circuit may be powered by a battery or any well filtered external DC power supply (You may

order the MAX186 IC from Radio-Sky Publishing, or from Digi-Key or Mouser Electronics, see Appendix) The A/D circuit can be built on a small breadboard or on a printed circuit board A circuit board and partial kit of parts (no case, connectors, or power supply) is available from Radio-Sky Before we begin building the single channel A/D converter you will need to secure a clean well lit work area You will need to locate a small 27 to 33 watt pencil-tipped soldering iron, a roll of 60/40 rosin core solder and small jar of Tip Tinner, a soldering iron tip cleaner/dresser Collect together a few small hand tools such as a pair of end-cutters, a pair of needle-nose pliers, a flat-blade and a Phillips screwdriver and a magnifying glass Grab the schematic, parts layout diagram and the resistor and capacitor identifications charts below, and we will begin This project employs eight 100,000 ohm resistors at the input to each of the A/D channels Take a look at the resistor identification chart in Table 24-1 Each resistor will have three or four color bands on the body of the resistor, which start at one end of the resistor body